- Patients with paroxysmal nocturnal hemoglobinuria have a high frequency of peripheral-blood T cells expressing activating isoforms of inhibiting superfamily receptors. Poggi, A., Negrini, S., Zocchi, M.R., Massaro, A.M., Garbarino, L., Lastraioli, S., Gargiulo, L., Luzzatto, L., Notaro, R. Blood (2005)